Patent Literature 1 discloses a technique of combining a plurality of wave winding coils each made of a conductor wound in a wave form so that the coils are displaced or offset from each other by one slot pitch.
If a stepped portion 223 shown in FIG. 3 of Patent Literature 1 is formed in one end of each conductor but which is not obviously described in the specification and drawings, the other end has to be formed with a reversed stepped portion conforming to the stepped portion 223. Otherwise, the coils are displaced in sequence and thus coil end portions could not be formed in circular shape.
If the reversed stepped portion is formed in the other end, two wave winding coils could not be combined in simple overlapping relation, which is not clearly described in Patent Literature 1. The two coils always need to be sequentially braided as disclosed in Patent Literature 1.